Synthesis and properties of CuO-doped Ce0.9Gd0.1O2-delta electrolytes for SOFCs

Abstract

The effects of copper oxide (CuO) addition on the crystal structure, densification and microstructure of Gd-doped ceria (Ce0.9Gd0.1O2-delta, CGO) synthesized by the polymeric precursor method have been studied. Ce0.9-xGd0.1CUxO2-delta (0 <= X <= 0.01) precursor powders were calcined at 600 degrees C for 1 h and the phase formation was studied by powder X-ray diffraction combined with Rietveld refinement analysis. Relative density measurements and microstructural analysis were performed on pellets sintered in the temperature range 1000-1100 degrees C in air. The effect of CuO as a sintering aid becomes more visible when its content is in the 0.5-1 mol% range where the relative densities are found to be 98% for sintering temperature as low as 1000 degrees C. A remarkable reduction (up to similar to 500 degrees C) in the sintering temperature for 1 mol% CuO-doped CGO ceramics is observed together with the formation of a dissolved phase of Gd2O3-CeO2-CuO. Ce0.89Gd0.1Cu0.01-yO2-delta sintered at 1000 degrees C shows total electrical conductivity of 15.5 mS cm(-1) at 600 degrees C slightly higher than Ce0.9Gd0.1O2-delta sintered at 1500 degrees C (12.4 mS cm(-1)). (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.